The present invention relates to chain spraying or lubricating apparatus and more particularly to a unique device which is self-contained, driven by the chain and which sprays a lubricant or other liquid to the friction or wear areas of the chain.
Various forms of overhead and infloor chain conveyors are presently available. Such conveyors are used in manufacturing facilities for transportation of parts on assembly lines, in warehouses or in various processing plants. Overhead chain conveyors typically include an elongated I-beam from which the chain is supported by a plurality of trolley assemblies. In order to insure proper operation of such systems, it is important that the pins connecting adjacent links be properly lubricated. With any oiling system or spraying apparatus, it is also important that the liquid be properly directed and that excess spray be avoided. In the food handling industries, for example, excessive lubricant dripping cannot be tolerated.
Various forms of chain lubricators and/or sprayers have heretofore been proposed for use with overhead chain systems and infloor chain or tow line conveyors. Such systems typically employ remote oil storage or reservoir tanks, motor driven pumps, and trip devices for activating a liquid spray. Such prior devices may be bulky, expensive and can result in excessive liquid spraying. Further, the liquid is not always properly directed to the high wear areas of the chain.
Commonly owned U.S. Pat. No. 4,159,046, entitled CHAIN LUBRICATION APPARATUS AND METHOD and issued on June 26, 1979, to Frost et al discloses a device which overcomes some of these prior problems. In one embodiment of the invention disclosed therein, the chain lubrication apparatus includes an oil tank supported on the overhead conveyor trolley beam. A sprocket wheel having a plurality of teeth is rotatably supported adjacent the chain so that the teeth are engaged by the chain. Each tooth supports a pair of spray nozzles. A metering valve, connected to the oil tank, is sequentially connected to each of the nozzles. The metering valve is air operated through a stationarily mounted air valve which is tripped by members on the sprocket. In a still further embodiment disclosed in this patent, a mechanically actuated piston or plunger forces liquid through internal conduits in a tooth to the spray nozzles. The plunger is actuated by a cam follower engaging a cam track.
Still further examples of prior lubricating or spraying systems may be found in U.S. Pat. No. 4,024,930, entitled LUBRICATING DEVICE AND METHOD and issued on May 24, 1977, to Thomson et al and U.S. Pat. No. 4,085,821, entitled LUBRICATION SYSTEM and issued on Apr. 25, 1978, to Kast et al. The system disclosed in U.S. Pat. No. 4,024,930 passes lubricating fluid through an inlet line into a shaft and to a piston chamber. The lubricating fluid is evacuated to a discharge device located on a sprocket. The sprocket and pump body defining the piston chamber are rotatably mounted. The pump is connected to a stationary tank through a lubricating inlet manifold.
The system disclosed in U.S. Pat. No. 4,085,821 includes a motor driven piston metering pump which delivers lubricant to a plurality of outlet ports. The outlet ports communicate with individual conduits which deliver lubricant to various portions of the conveyor system. A control unit including an electrical switch and a feeler arm control a clutch which connects the electric motor with a pump shaft.